bradley



J. W. BRADLEY. EXPANDING BORING HEAD AND SCREWING HEAD.

APPLICATION FILED JAN- 30' I913.

Patented A11 15, 1916.

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J. W. BRADLEY.

EXPANDING BORING HEAD AND SCREWING HEAD.

APPLICATION FILED JAN- 30. 1913.

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JOHN WILLIAM BRADLEY, 0F LEEDS, ENGLAND.

EXPANDING BOBING-HEAD AND $CRE'WING-I-IEAD.

To all whom it may concern:

Be it known that 1, JOHN VILLIAM BRAD- Lm', a subject of the King of Great Britain and Ireland, residing at Leeds, in the county of York, England, have invented new and useful Improvements in Expanding Boring-Heads and screwing-Heads, of which the following is a specification.

This invention relates to an improved ex-l jaws carrying the cutters or dies, whereby the expanding and collapsing movement is positively and accurately controlled without the application of springs to the cutters or dies, in the devices for mounting and securing said cam plate, in the devices for mounting, adjusting, and locking the spring pressed locking plunger which engages the cam plate, and in the devices for obtaining an exact adjustment of the cutters or dies for each successive cut by means of an index finger carried by the plunger and working in conjunction with a graduated scale.

Description of drawings-Figure 1 is an end elevation; Fig. 2 a sectional side elevation, and Fig. 3 a plan, of an expanding and collapsing boring and screwing head constructed in accordance with my invention. Fig. 4.- is a plan, Fig. 5 a side elevation, and Fig. (3 an end elevation, illustrating the adaptation of my improved expanding and collapsing boring and screwing head for use in an automatic turning machine. Fig. 7 is a side elevation illustrating the adaptation of my improved expanding and collapsing boring and screwing head, with automatic collapsing motion, for use in a boring or like machine.

According to my said invention the tools or dies A (four or more) are carried in jaws B which are slidably fitted in corresponding external recesses or pockets within the main body C of the head, each tool or die A being held in position within its-jaw B by means of a tapered gib D and screw E, or by means Specification of Letters Patent. Pgwqgntgd A n- 15, 31913 Application filed January 30, 1913.

Serial No. 745,280.

of a lateral pinching screw or other convenient device. The series of sliding jaws B are adjusted radially within their recesses or pockets by means of an intermediate cam plate F having a corresponding series of projecting cam rises G engaging within female recesses in the sliding jaws B. The said cam plate F is held up to the sliding jaws B by means of an outer disk or plate H fitting on a projecting boss I of the main body C of the head, this outer disk or plate H being locked up to a shoulder J of the body C by means of annular check nut or lock nut K, which itself is locked by a series of grub screws L. This outer disk or plate 'H has an internal circumferential. recess M,

extending around asuitable part of its circumference, within which is fitted a cylin drical tension spring N connected at one end to the outer disk or plate H and at the other end to the intermediate cam plate F. The outer disk or plate H is provided also with a circumferential slot 0 of suitable length having a recess P on its inner face, and within this slot 0 is fitted a sliding block Q having a corresponding inner shoulder R engaging within the said recess P. This sliding block carries a cylindrical plunger box S within which is fitted a spring plunger pin T adapted to engage with a hole U in the face of the intermediate cam plate F. The outer end of the plunger box S is fitted. with a nut V for locking the sliding block Q and its plunger box S within the circumferential slot 0, and between said nut V and the face of the outer disk or plate H is interposed an index finger lV working in conjunction with a scale X (graduated say in thousandths of an inch) on the outer edge of the disk or plate H. In small sizes of boring and screwing head it may be found convenient to make the cam rises G of the cam plate F engage direct into recesses formed in the tools or dies A, thus dispensing with the jaws-B; the sliding block Q and cylindrical plunger box S may also be formed in one piece.

The action is as follows :-The sliding plunger block Q is first set to zero mark on the scale X, and is locked in that position. The cam plate F is then rotated by means of a pin inserted in holes Y so as to expand the sliding jaws B and their tools or dies A, until when the hole U in the cam plate F comes opposite the spring plunger pin T, the latter at once engages the hole and locks the mechanism in its first cutting position. On completion of the first cut, the spring plunger pin T is withdrawn (by hand or by suitable automatic mechanism) and the cam plate-F reverts to its original position under the influence of the cylindrical tension spring N, thus contracting the tools or dies A clear of the work and enabling the apparatus to be withdrawn. If a further out or cuts is needed, the sliding block Q is slackened and re-adjusted within its circumferential slot 0, the index finger W and graduated scale X giving the exact diameters required for each succeeding out.

In adapting my invention for use in an automatic turning machine, the appliance is mounted in a hole in the turret 1 (Figs. 4 to 6), and as the turret advances to complete its stroke, a stop carried in the cut-elf rest (not shown) will engage the head Z of the spring plunger pin T, arresting its travel and withdrawing the pin out of its register hole U in the cam plate F. The spring N Will then rotate the cam plate F and collapse the sliding jaws B. When the turret 1 retates, a finger 2 (connected to the cam plate F through a circumferential slot 3 in the outer. disk or plate H) will strike a stop t and rotate the cam plate F back again until the spring plunger pin T reengages its register hole U, when the appliance will be in correct position for the next piece to be operated upon.

To make the appliance automatically collapse in a boring or like machine, a long key 5 (Fig. 7) engaging a hole in the head Z of the spring plunger pin T is arranged to slide in a keyway or spline 6 in the bar 7 which carries the appliance, and a sliding collar 8 connected to the long key 5 is set to the distance required. As the bar 7 traverses the appliance through the hole to complete the cut, the progress of the collar 8 is arrested at the desired point by a stop 9 on the machine table 10, thus withdrawing the spring plunger pin T and allowing the spring Nto rotate the cam plate F and collapse the jaws B and cutters A.

I claim:

1. In an expanding and collapsing boring and internal screw threading head, in combination a body portion, a rotatable cam plate mounted in the body and having projecting cams thereon; radially disposed slidable tool holding jaws having recesses adapted to engage with said projecting cams; the formation of two concentric slots in the rear of said head, an adjustable plunger box clamped in one of said slots, having an index finger adapted to cooperate with a graduated scale on the rear end of said head, a spring plunger in said box adapted to enter an orifice formed in said cam plate, a head on the exterior end of said plunger having radial orifices therein, a shank for said boring and screwing head, having a longitudinal slot therein, a trip key slidabl y secured in said slot in said shank and having a projecting part engaging with one of said radial orifices in said plunger head, means for automatically causing said jaws to retire by engaging said trip key and thereby removing said plunger from said spring operated cam plate, means for automatically re-setting said jaws in their desired operative position, comprising a pin secured to said rotatable cam plate and extending through said other concentric slot in the rear face of said head; a bracket or the like adapted to engage said pin and thereby rotate said cam plate until said plunger engages with its orifice in said cam plate.

2. In an expanding and collapsing boring and internal screw threading head, in combination, a rotatable cam plate having projecting cams thereon, radially disposed slidable tool holding jaws having recesses adapted to engage with said projecting cams, a slidably mounted plunger adapted to hold the cam plate in an operative position, spring means of rotating said cam plate, a pin projecting from said cam plate axially parallel therewith, and adapted to engage with a projecting part of a lathe or the like and automatically re-set said cam plate in its normal operative position, and means for automatically disengaging the plunger from the cam plate.

JOHN WILLIAM BRADLEY.

'Witnesses:

J orIN E. VVALSH, ALLEN BENNETT.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

